The standard error (SE) of the mean is the standard deviation (SD) divided by the square root of the number in the sample.
In this case, your Z score would be ($1075-$1100)/SE. Find the Z score and look it up in the back of your statistics text in a table labeled something like "areas under the normal disrtibution."
I hope this helps. Thanks for asking.
I cant figure this out!!!
The income of trainees at a local mill are normally distributed with a mean of $1100 and a standard deviation of $150. If a sample of 100 trainees is selected, what is the probability that the sample mean will be less than $1075 month?
3 answers
Still don't get it...sorry. I am really trying to get it without asking for the answer, but I just don't get it. Help please.....
Your SE = SD/sq.root of n
SE = 150/10 = 15
For a distribution of sample means, the Z score = (1075-1100)/15.
Can you calculate the Z score and use it in the table to find the probability?
I hope this helps a little more. Thanks for asking.
SE = 150/10 = 15
For a distribution of sample means, the Z score = (1075-1100)/15.
Can you calculate the Z score and use it in the table to find the probability?
I hope this helps a little more. Thanks for asking.